Is It Okay To Take Antihistamines Before an Allergy Test?

Posted on by Goodyear Office

If you have a pollen allergy, something as simple as taking your kids to play at Palm Valley Park can lead to a bout of sneezing and hives. When your symptoms arise, you’ll probably reach for your handy antihistamines. Antihistamines are an excellent option for symptom relief. However, if you have an allergy test coming up in less than a week, they might not be such a good idea.

Whether you can use antihistamines depends on the type of test you take.

Antihistamines and Blood Tests

A box of antihistamines sitting on a desk.

Blood tests look for an allergy-fighting antibody in your body called immunoglobulin E (IgE). When you encounter a substance you’re sensitive to, like pollen in the park, your body releases extra IgE to protect itself. Those elevated levels in your blood will indicate an allergy.

Antihistamines will not interfere with the IgE levels in your blood, meaning they’re safe to take leading up to a blood test.

Antihistamines and Skin Tests

Skin tests work a little differently. During the test, we’ll introduce a small dose of the suspected allergen into the skin by scratching or pricking the skin. After that, we’ll wait about 15 minutes to see if a reaction occurs—usually in the form of red hives. In some cases, the reaction will arise after the 15 minutes.

Because skin tests focus on visual symptoms, and antihistamines suppress symptoms, you will need to avoid taking the medication for five days[1] before your test. A few forms of antihistamines to avoid include:

  • Pills
  • Syrups
  • Eye drops
  • Nasal sprays
  • Creams

A few medications that often contain antihistamines include:

  • Decongestants (often come as a decongestant/antihistamine hybrid)
  • Sleep aids containing diphenhydramine (diphenhydramine is a type of antihistamine)
  • Flu and cold medications

Double-check the label of any medication you take within five days of the test to ensure it doesn’t contain surprise antihistamines.

Stopping Other Medications

There are a few other types of medications you may need to stop taking before your test, like corticosteroids or certain antidepressants. That doesn’t mean you should stop taking any medication before talking to a medical professional. Stopping medication without medical supervision can lead to bad side effects. Do not stop taking any medication before talking to your allergist and the provider who prescribed it.

For more information on preparing for your allergy test, contact Goodyear Office today to speak with one of our specialists.

[1] American Academy of Otolaryngic Allergy. (2021, February 1). Medications to stop before allergy testing. https://www.aaoallergy.org/medications-to-stop-before-allergy-testing/